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The application of laser in dentistry began with Gordon (1964) 1 and Stern et al (1966) 2 . Since then many applications have been done, such as its use in fixed cavities, treatments of soft tissue and surgical cuts among others. The preventions of defects in bones and fillers of dental cavities constitued a problem for the biomedical research. The aim of this work was to determine the morphological changes of the Human Dental Enamel (HDE) and bovine 2 hydoxyapatite by means of the application laser of CO 2 and their fusion effect of these biomaterials for dental and orthopedic applications. Ten third molars extracted from young adults patients (between 18 to 25 years old) forclinical reasons, were used in five blocks and five of them were powdered. And powder and bulk samples of bovine hydroxyapatite were used. For the morphochemical characterization a Scannin Electron Microscopy Jeol 5900 LV that has attached and OXFORD ISIS EDS equipment. The CO 2 laser used was a Kuvars IV (LX 20) with wavelengh of 10.6µm, excitation frecuency of 40 to 45 MHZ, maximun beam diameter of 0.3 mm and 2 to 5 watts seconds with a water cooling system. For this work the condition were time of expantion of 0.3 secibds, distances from 5 cm and frequency 50 to 60 Hz. hexagonal structure (fig 1). There was not any presence of calcium oxide in the EDS analysis so that it can not supposed to take part on the composition and micro explotions that taked place which originated the waste of materials and microholes that are occupied ionically, diminishing the permeability, for the loss of water, carbonates and organic substance. Craters and borders were also observed suggested during the laser interaction. The effects will depend on the energy density and orientation of the prisms besides for coefficient of absorption of the water (fig.2). During interaction a vibration was observed in the bond potential of the crystaline and molecular lattice in such a way that this molecules fused and recrystallized recovering References( 1) Gordon T. E. Some effects of laser impacts in extracted teet. J.Dent. Research (2) 1964 372-375 (2) Stern R.H, Sognages RF, Goodman F. Laser effect on in vitro enamel permeability solubility. JADA 73(4) 1966m 838-843 (3) We thank the technical help from Iván Puente, Jaqueline Cañetas, Alfredo Sanchez , Samuel Tehuacanero and DGAPAUNAM, project 1N104902, sponsored this work

Amaranthus is a dicotyledonous pseudocereal and one of the new world's oldest crops, having originated from Meso-America and was a major food crop of the Aztecs. Popularity in the cultivation and consumption of Amaranthus seed in the modern era began in the mid-1970s with the rediscovery and promotion of amaranth due to its superior nutritional attributes as compared to cereal grains. Amaranth plant has a high-quality protein, carbohydrates, unsaturated oil, squalene, dietary fiber, tocopherols, phenolic compounds, flavonoids, vitamins and minerals. The amaranth's grain was collected at San Martin Pahuacan, Estado de Mexico, Mexico. The used methodology is gamma spectrometry with Hyperpure Germanium detector (HPGe) and Multichannel Analyzer (MCA) with Maestro ® software. The result shows a unique concentration of radioactive potassium content in the amaranth protein isolated from amaranth grains is 424.1 mg/100 g of amaranth protein. There is an excellent agreement between the amount of potassium determined by atomic absorption spectroscopy in our laboratory and the value obtained in this work using the Gamma Spectrometry Technique.

The aim of this work was to characterize six different eggshell types as future osseous regeneration scaffolds. The study design was cross-sectional observational. The study was conducted in the Laboratory of Materials and the chemical analysis in the Faculty of Chemistry, UNAM, Mexico. Fifty samples of fresh eggs were obtained, 10 from each species (hen, turkey, duck, dove and quail). Square-shaped pieces of about 2 x 2 cm were obtained from the eggshells by means of a high-speed handpiece with a # 701 carbide bur. From the total of eggshell pieces, the ones coming from fresh eggs were included, and the ones showing signs of fracture or spots were excluded. Their morphology was analyzed with a low vacuum scanning electron microscope (JEOL 5200), with an accelerating voltage of 20 kV. The chemical elemental analysis was performed with an EDAX energy dispersive spectrometer (EDS) and the chemical composition was determined by means of a Siemens diffractometer. All of the eggshells were constituted by calcium carbonates, and their outer structure was less porous than the inner one, sometimes with granules and cuticles firmly attached to the inner surface of the eggshell. The eggshell major chemical components were mainly: oxygen, calcium, phosphorous, magnesium, sulfur and carbon. There are no significant quantities of sulfur (S) in the turkey and quail eggshells. These kinds of eggshells have not been tested yet as a scaffold, but it is expected that they may be used soon in bone regeneration once the organic part is removed. Eggshells are largely waste material. The authors anknowledge the technical support to Chem. Rafael Ivan Puente Lee